Reset Admin panel?

Hi all, I installed a customisation app , I cannot get it to work in my theme.
Well, I can get the custom text input box to display on product page, but the product will not add to cart.
It did add to cart a few times, but stopped, without me changing anything?
I am a complete beginner, but have tried to troubleshoot, I wont list everything I tried, but I just created a brand new Shopify store, completely separate from the first, same issue cannot add to cart, I installed new theme in new store, after deleting customisation app, and the original theme, I cannot add to cart from the newer theme.
So I would like to try and reset the whole admin side, is this possible?

Thanks in advance.

M

What kind of personalisations are you trying to add??

Does it give users a live view of the customization or you just need some info from the users as additional details along with the order?

And just to answer your question, I dont think or atleast I don’t have knowledge of a setting where we can reset the admin panel entirely other than the one you tried, of creating a new store.

Best